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A scientific fact/tidbit you recently learned that you thought was interesting

Surprised they were kept as pets. I know quite a few people that have been bitten by squirrels, they can be right vicious barstools when they are cornered. Would have thought the being bit by the wild ones would have been the more probable source of cross infection.
 
Surprised they were kept as pets. I know quite a few people that have been bitten by squirrels, they can be right vicious barstools when they are cornered. Would have thought the being bit by the wild ones would have been the more probable source of cross infection.

Leprosy is an old infection in humans. Squirrels have human leprosy (and only in Britain), so it almost certainly went from humans to squirrels. All the mediaeval illustrations show squirrels as pets of women, perhaps they just don't like men! Leprosy is airborne spread by droplets from the airways, and probably needs prolonged exposure, so escaped or freed pet seems more likely. A squirrel catching it from biting a man seems less likely.
 
Surprised they were kept as pets. I know quite a few people that have been bitten by squirrels, they can be right vicious barstools when they are cornered. Would have thought the being bit by the wild ones would have been the more probable source of cross infection.

You do know that squirrels were so named because they were owned by Squires and Earls, right?

Huh, that almost sounds reasonable.
 
You do know that squirrels were so named because they were owned by Squires and Earls, right?

Huh, that almost sounds reasonable.

That's not right!
They were aquatic until the 1400's and were related to both squids and eels. The archaic pronunciation of squid was 'skwii'.
I read that on the internet, so I know it's true!
;)
 
That's not right!
They were aquatic until the 1400's and were related to both squids and eels. The archaic pronunciation of squid was 'skwii'.
I read that on the internet, so I know it's true!
;)

I think we're going to have to agree to disagree on this one (by which I mean, agree that you're wrong and disagree that I'm wrong).
 
This was supposed to be the case, Rising levels of CO2 in the atmosphere drive an increase in plant photosynthesis—an effect known as the carbon fertilization effect (Jan 27, 2022), but apparently plants find it harder to absorb carbon dioxide amid global warming (New Scientist, Aug 10, 2023):
A modeling study suggests that increases in photosynthesis have slowed since 2000, opposing previous research that said this effect would remain strong, helping to absorb CO2 from the atmosphere
 
Sámi tribes, according to the Arktikum Science Museum in one of their exhibitions re the Aurora Borealis, believed that these spooky wavering lights in the northern winter sky were spirits and that these spirits were speaking to them. They would put all their worldly goods onto a sled and cover them over, out of some kind of fear of these supernatural events.

Of course, thanks to noticing the effect on a compass needle when the northern lights are active, scientists were able to ascertain that the lights were the result of geomagnetic phenomena.

When a solar storm comes toward us, some of the energy and small particles can travel down the magnetic field lines at the north and south poles into Earth's atmosphere. There, the particles interact with gases in our atmosphere resulting in beautiful displays of light in the sky. Oxygen gives off green and red light.

What Is an Aurora? - NASA Space Place

NASA Space Place (.gov)
https://spaceplace.nasa.gov › aurora

Here's the thing. It wasn't until 2012 that an acoustics researcher at Aalto University recorded the 'voices' which were apx 70 metres above the ground during the appearance of the northern lights.

[Professor Unto K Laine] recorded hundreds of sound events in Fiskars where the temperature was at -20 °C. I selected the 60 loudest events, the sources of which were directly above the recording microphone array. The magnetic pulses that preceded these sounds proved that their sources were at an altitude of approximately 75 metres. On the same night, the Finnish Meteorological Institute carried out its own measurements, which proved that the inversion layer was located at the same altitude where these noises were born. The correlation between the strength of the magnetic pulses and the loudness of the sounds was also strong.

So whilst people assumed the Sámi were just being superstitious, they knew about these northern light noises all the time.

The science behind the sounds is as follows:

According to the new inversion layer hypothesis, the popping and crackling sounds associated with the Northern Lights are born when the related geomagnetic storm activates the charges that have accumulated in the atmosphere's inversion layer causing them to discharge.

'Temperatures generally drops the higher the altitude. However, when temperatures are well below zero and, generally in clear and calm weather conditions during the evening and night, the cold is near the surface and the air is warmer higher up. This warm air does not mix, instead rising up towards a colder layer carrying negative charges from the ground. The inversion layer forms a kind of lid hindering the vertical movements of the charges. The colder air above it is charged positively. Finally, a geomagnetic storm causes the accumulated charges to discharge with sparks that create measurable magnetic pulses and sounds' Mr Laine, who is now a professor emeritus, explained.
https://www.aalto.fi/en/news/acoustics-researcher-finds-explanation-for-auroral-sounds
 
I think I've heard it said that gravity is not a force.

Also the electromagnetic force and the weak force are actually the same force: the Electroweak force. So that would get it down to only two forces: The strong force and the electroweak force.
 
I think I've heard it said that gravity is not a force.

Also the electromagnetic force and the weak force are actually the same force: the Electroweak force. So that would get it down to only two forces: The strong force and the electroweak force.


According to Einstein it is generated by the warping of space time. (My understanding of the science :blush:)


What happens at quantum level? :confused: Who knows.
 
I think I've heard it said that gravity is not a force.

In a sense, yes. Force = mass * acceleration, but only if you're measuring acceleration from an inertial reference frame.

In a non-inertial reference frame, you can get all sorts of pseudo-forces like the centrifugal and coriolis force in rotating reference frames. These forces aren't real, they are artifacts of working in a non-inertial reference frame.

In general relativity, you actually cannot have global inertial reference frames, you can only have locally inertial reference frames. And a locally inertial reference frame is a free-falling reference frame. Objects not acted on by a force will follow a geodesic (the curved space equivalent of a straight line) through spacetime. So falling is a force-free activity, and gravity isn't a force. Other forces act on objects to accelerate them away from their geodesic, but gravity doesn't. Gravity warps spacetime to change what the geodesic is, but it doesn't push objects off their geodesic.
 
I recently learned (or re-learned yet again) that turtles don't live in their shell, they are their shell. Or rather the shell developed mainly from their ribs. Too many kids cartoons owning space in my brain.
 

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